Electromagnetically operated distribution valve for a pneumatic system

ABSTRACT

An electromagnetically actuatable pneumatic directional control valve having a compressed air network connection, a vent and at least one working connection for a compressed air consuming unit. In order to achieve a modular building-block system with a simpler, more efficient assembly and combination of a number of valves into an integral valve block, a working conduit that leads to the working connection, ventilation conduits and a supply conduit that leads to the vent and the compressed air network connection, the vent, and a valve member that has an actuation magnet and controls the conduits are combined in a valve housing. The connections for the compressed air network and the compressed air consuming unit are disposed in a connecting plate that can be separated from the valve housing. The compressed air network connection is comprised of a connection fitting on the one plate side and a connecting bore connected to it on the remote plate side of the connecting plate so that the connecting fitting and connecting bore of connecting plates of two directional control valves disposed next to each other can be plugged into each other and can be connected to each other via connecting means disposed on these plate sides.

PRIOR ART

The invention is based on an electromagnetically actuatable pneumaticdirectional control valve.

Directional control valves of this kind are used in utility vehicles foractuating pneumatic auxiliary units, such as differential locks,actuation of the engine brake, transmission control, luggage compartmentflap actuation in busses, etc. from the driver's cab. The directionalcontrol valves are most often combined into a so-called valve blockwhich is connected to a compressed air supply line. The number of valvesin a valve block is determined by the number of pneumatic auxiliaryunits to be connected.

The directional control valves are embodied as both electromagnetically,directly actuated valves and electromagnetically pilot-controlledvalves. In the latter, a pneumatically actuated main valve is switchedby an electromagnetically actuated pilot-control valve. It is standardto use both types of valve in the same vehicle.

In a known directional control valve of the type mentioned at thebeginning (U.S. Pat. No. 4,524,797), the supply conduit leading to thecompressed air network connection and the ventilation conduit leading tothe vent are disposed flush with each other in a valve housing and atright angles to the working conduit leading from the working connection.The magnet coil of the electromagnet rests coaxially on a cylindricalhousing part of the valve housing, which housing part contains thesupply conduit. The cylindrical armature of the electromagnet is guidedso that it can move axially on the inside of the housing and constitutesthe valve member, which rests alternatingly on one of the two valveseats, which are embodied at the conduit mouths of the supply conduitand the ventilation conduit. Depending on the position of the valvemember, the working conduit is connected to the ventilation conduit orthe supply conduit. For the purpose of fastening the directional controlvalve to a carrier plate in the motor vehicle, pins protrude from thevalve housing, which extend at right angles to the supply conduit. Whencombining a number of valves into a valve block, the valves are attachedto the carrier plate next to one another in a parallel alignment of thesupply conduits and the compressed air network connections of theindividual valves are connected to one another by means of individualplug adapters. The plug adapters are plugged into one another and arerespectively slid onto the compressed air network connection on thevalve housing. The first plug adapter carries a connection fitting forthe compressed air supply line; the last plug adapter is closed off atthe end by means of a stopper.

ADVANTAGES OF THE INVENTION

The directional control valve according to the invention, has theadvantage that by means of the division into the valve housing and theconnecting plate with the corresponding arrangement of the connectionfittings and connecting conduits as well as the embodiment of theconnecting means on the connecting plate, not only is a modularbuilding-block system achieved for constituting the two necessary typesof valves out of largely equivalent elements, but it is also possible tocombine the valves into a valve block in an essentially simpler and moreefficient manner. The connecting plates of a number of valves connectedto the valve housing are simply placed against one another, wherein theconnection fitting of the compressed air network connection of the onevalve is plugged into the connecting bore of the compressed airconnection of the neighboring valve, and they are then connected to eachother with positive engagement via the connecting elements. The assemblyprocess takes place without tools in an extremely short time. Separateconnecting means, such as the plug adapters in the known directionalcontrol valve are no longer necessary. Tolerance problems do not occurdue to the radially sealing O-rings between the connection fitting andconnecting bore. The O-rings are pre-installed and lie protected in theconnecting bores of the compressed air network connection. Thedisassembly of the valve block is carried out by means of a flat object,with the aid of which the connecting means are released, which arepreferably embodied as detent mechanisms. As a result of the extremelylow assembly and disassembly time, a considerable cost reduction isproduced both in manufacturing and in servicing procedures.

The modular building-block system that can be constituted with thedirectional control valve according to the invention includes a uniformvalve housing and two different embodiments of connecting plates as wellas a closure element for closing the connecting bores of the compressedair network connection. The two connecting plate variants are embodiedidentically on the outside, i.e. they have the same connection fittingsand connection bores of the compressed air network connection as well asthe same connection means. Only the inside of the connecting plate ischanged in so far as a purely conduit device is integrated into theconnecting plate for directly connected valves, and in addition to theconduit embodiment, a pneumatically actuated seat valve is integratedinto the connecting plate for pilot-controlled valves. As a result ofthe thus far equivalent embodiment of the connecting plates, differentvalve types can be combined into one valve block as needed withoutcausing problems.

Advantageous embodiments and improvements of the electromagneticallyactuatable directional control valve are possible by means of themeasures taken in the remaining claims.

According to a preferred embodiment of the invention, a stepped plug-infitting with two coaxial fitting sections of different diameters isembodied on the bottom of the valve housing and a stepped plug-in borewith two coaxial bore sections of different diameters is embodied on thetop of the connecting plate. The plug-in fitting can be plugged into theplug-in bore in a sealed fashion with the interposition of a radiallysealing O-ring between each fitting and bore section. The supply conduitfeeds into the circular end face of the smaller diameter fitting sectionand the working conduit feeds into the annular end face of the largerdiameter fitting section. The smaller diameter bore section of theplug-in bore is connected to a connecting conduit which joins theconnection fitting to the connecting bore of the compressed air networkconnection in the connecting plate. The connecting plate is embodied fora directional control valve that is directly actuated by theelectromagnet, so that the larger diameter bore section of the plug-inbore communicates with the working connection and is embodied for apneumatically actuated valve that is pilot-controlled by theelectromagnet, so that the larger diameter bore section of the plug-inbore feeds into a connecting conduit which can communicate via a controlconduit with a work chamber of a seat valve, which chamber is defined byan advancing piston. Via a valve tappet, the advancing piston actuates avalve plate which opens or closes a valve opening. The valve openingjoins the working connection on the connecting plate to the connectingconduit between the connection fitting and the connecting bore of thecompressed air network connection in the connecting plate.

According to a preferred embodiment of the invention, the housing andthe connecting plate can be connected to each other in detent fashion,for which purpose detent openings are provided, along with detentprojections that can snap into them. The detent projections arepreferably disposed protruding radially on the circumference of thevalve housing and the detent openings are disposed on the connectingplate. By means of this detent connection, it is very simple to mountthe individual valve, wherein there are no tolerance problems thanks tothe radially sealing O-rings between the plug-in fitting of the valvehousing and the plug-in bore in the connecting plate. The O-rings arepre-installed in a protected fashion and do not require any specialhandling during valve assembly.

According to an advantageous embodiment of the invention, in order toclose the connecting bore of the compressed air network connection inthe connecting plate, a closing element is provided, which carriesconnecting elements on one side of the closing element, which correspondto the connecting means that are for producing a connection and aredisposed on the plate side of the connecting plate that carries theconnecting bore. The closing element carries an axially protruding pinwhich projects into the connecting bore and seals it in an airtightfashion by means of a sealing ring. When the valve according to theinvention is used as a single valve, each valve requires a closingelement of this kind, which closes the connecting bore of the compressedair network connection. When a number of individual valves are combinedinto a valve block, the closing element is merely affixed to theconnecting plate of the last valve. The closing element is easy toproduce as an injection molded part and in turn can be installed withouttools. Installation and removal take place in the same manner as withthe connecting plates in relation to one another.

According to an advantageous embodiment of the invention, attachingmeans for the spatial fixing of the connecting plate are provided on aplate side of the connecting plate that extends between the two platesides that carry the connection fitting or the connecting bore. Thesefastening means preferably include a fastening plate formed onto theconnecting plate and of one piece with it, with two fastening eyesdisposed on it. By means of screws inserted through the fastening eyes,each valve can be individually fastened to the vehicle frame or to acarrier plate held on the vehicle frame. Only short screws are requiredfor fastening, which saves installation time, material costs, andweight.

For the electrical contacting of the electromagnet, according to anotherembodiment of the invention, the electrical connections of the magnetcoil of the electro-magnet are routed to a two-pole plug that can beaccessed on the valve housing from the outside and that has two plugpins that are each connected to a winding end of the magnet coil. Theplug is covered by a plug cap that carries two plug sleeves that can beslid onto the plug pins. For use in valve blocks, a number of plug capsare connected to an electric bus which is realized by means of anextrusion coated stamped grating. The bus has a number of stripconductors whose number is one greater than the number of plug caps.Each of the two plug sleeves of a plug cap is connected to a stripconductor that is shared by all of the plug caps and the other plugsleeve is connected to a separate strip conductor. All of the stripconductors are routed on the end to a separate electrical contact of anelectrical connecting plug. For a bus that is for supplying current tothree valves in a valve block, preferably a connecting plug according toDIN 72 585 is used, which has four electrical contacts which areconnected to the four strip conductors of the bus in the mannerdescribed. The plug caps are radially sealed at the bus and the plugsare radially sealed at the valve housings of the valves that arecombined into the valve block.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in detail in the description below inconjunction with exemplary embodiments represented in the drawings.

FIG. 1 is a front view of an electromagnetically controlled pneumaticdirectional control valve,

FIG. 2 is a top view of the valve in FIG. 1,

FIG. 3 is a side view of the valve in FIG. 1,

FIG. 4 is a section of the valve along the line IV—IV in FIG. 3,

FIG. 5 is a representation of the valve that is similar to FIG. 3, butis enlarged and shown in a partially sectional manner,

FIG. 6 is a front view of the valve housing of the valve in FIG. 1,

FIG. 7 is a section of the valve housing according to line VII—VII inFIG. 6,

FIG. 8 is a front view of an electromagnetically pilot-controlledpneumatic directional control valve,

FIG. 9 is a top view of the valve in FIG. 8,

FIG. 10 is a side view of the valve in FIG. 8,

FIG. 11 is a representation similar to the one in FIG. 10, but isenlarged and shown in partially sectional fashion,

FIG. 12 is a front view of a valve block comprised of three valves,

FIG. 13 is a circuit diagram of the valve block in FIG. 12,

FIG. 14 is a side view of two valves placed against one another beforeproduction of a fixed connection in the valve block,

FIG. 15 shows a detail of an enlarged representation of connecting meansbetween two valves combined into a valve block,

FIG. 16 is a side view of a bus for electrically contacting the valveblock in FIG. 12, in a partially sectional view,

FIG. 17 is a schematic representation of a top view of a stamped gratingof the bus in FIG. 16,

FIG. 18 is a front view of a closing element,

FIG. 19 is a view of the closing element according to arrow XIX in FIG.18.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The electromagnetically actuated pneumatic directional control valve 10shown in different views and sectional representations in FIGS. 1-5 isembodied as a 3/2-way solenoid valve, which in a known manner, has acompressed air network connection 11, a vent 12, and a workingconnection 13 for a compressed air consuming unit. The circuit symbolfor this 3/2-way solenoid valve is shown on the right in FIG. 13. Asdepicted there, in the unexcited starting position of the valve, theworking connection 13 is connected to the vent 12 and closed off inrelation to the compressed air network connection 11, and in the excitedoperating position of the valve, this working connection 13 is connectedto the compressed air network connection 11 and is closed off inrelation to the vent 12. To this end, as can be seen from the sectionalrepresentations in FIGS. 4 and 5, a supply conduit 15 that leads to thecompressed air network connection 11, a ventilation conduit 16 thatleads to the vent 12, and a working conduit 17 that leads to the workingconnection 13 feed in a valve chamber 14.

The supply conduit 15 and the ventilation conduit 16 are flush with eachother and each have a valve seat 18 or 19 on their conduit mouth in thevalve chamber 14, against which seats a valve member 20 alternatinglyrests. The valve member 20 is fastened to an armature 20′ of anelectromagnet 21, which armature is embodied as a disk-shaped, stampedsheet metal part, and the magnet coil 22 of this electromagnet 21 isdisposed coaxial to the ventilation conduit 16. The valve member 20 ispressed against the valve seat 18 at the supply conduit 15 by a valvespring 23 when the magnet coil 22 is unexcited so that this supplyconduit is closed off and the working connection 13 communicates withthe vent 12. When the magnet coil 22 is excited, the valve member 20lifts off from the valve seat 18 and presses against the valve seat 19on the ventilation conduit 16. As a result, the ventilation conduit 16is closed off and the working connection 13 communicates with thecompressed air network connection 11.

In order to realize a modular building-block system for building thedirectional control valve, the electromagnet 21 is combined with themagnet coil 22, the valve chamber 14 with the valve member 20, theworking conduit 17, the supply conduit 15, and the ventilation conduit16 with the valve seats 18, 19, and the vent 12 in a valve housing 24,while the connections 11, 13 for the compressed air network and thecompressed air consuming units are placed into a connecting plate 25that can be separated from the valve housing 24, which connecting plateis detachably connected to the valve housing 24. In this manner, oneobtains a standardized valve housing 24, as shown in FIGS. 6 and 7,which housing can be connected to differently conceived connectingplates 25. Depending on the design of the connecting plate 25, anelectromagnetically, directly actuated directional control valve 10according to FIGS. 1-5 or an electromagnetically pilot-controlleddirectional control valve 10′ according to FIGS. 8-11 can be produced.The valve housing 24 is embodied of two parts and is comprised of alower housing part embodied as a stepped plug-in fitting 26 and an upperhousing part that is embodied as a cap 27 that partially covers theplug-in fitting 26. The cap 27 has a pin-shaped center part 271 in whichthe ventilation conduit 16 extends coaxially and onto which the magneticcoil 22 is placed. The coil ends of the magnetic coil 22 are guidedthrough the cap 27 and electrically connected to both plug pins 28, 29of a two-pole plug 30. The plug 30 is secured on the side of cap 27. Theplug-in fitting 26 has two fitting sections 261 and 262 with differentdiameters. In the plug-in fitting 26, the supply conduit 15 is embodiedas a coaxial bore and the working conduit 17 is embodied as an annularchamber coaxial to it, which communicates with the valve chamber 14 viaan inlet opening 31 in the armature 20′ and with an outlet opening 32,feeds into the annular end face of the larger diameter fitting section261. The mouth 33 of the supply conduit 15 is disposed in the circularend face of the smaller diameter fitting section 262.

In the connecting plate 25 that is detachably connected to the valvehousing 24, the compressed air network connection 11 is shown in thesectional representation according to FIG. 4 and the working connection13 is shown in the sectional representation according to FIG. 5. Thecompressed air network connection 11 includes a connection fitting 34that can be accessed on the one plate side 251 of the connecting plate25 and a connecting bore 35 positioned on the opposite plate side 252 ofthe connecting plate 25, which bore communicates with the connectionfitting 34 via a coaxial connecting conduit 36 (FIG. 4). The connectionfitting 34 is realized by a screw sleeve with internal thread, which isformed in a pressure tight manner into the connecting plate 25 comprisedof plastic and can be adapted to different thread sizes, thread forms,and sealing systems. The connection fitting 34 and connecting bore 35are matched to each other so that the connection fitting 34 can beplugged into the connecting bore 35 in an airtight manner, with theinterposition of a radially sealing O-ring 37. In order to illustratethis, FIG. 4 shows a detail of the connecting plate 25′ of a neighboringdirectional control valve with a detail of the connecting bore 35 shown.The sectional representation shows how the connection fitting 34 of theconnecting plate 25 plugs into the connecting bore 35 of the neighboringconnecting plate 25′ and how the plug connection is sealed by the O-ring37.

A stepped plug-in bore 38 is let into the top side 253 of the plug-inplate 25 and has two coaxial bore sections 381 and 382 that havedifferent bore diameters. The bore sections 381 and 382 are adapted tothe fitting sections 261 and 262 of the plug-in fitting 26 on the valvehousing 24 in order to receive them so that when the plug-in fitting 26is plugged into the plug-in bore 38, the fitting sections 261 and 262rest in a sealed fashion in the associated bore section 381 or 382, withthe respective interposition of a radially sealing O-ring 39 or 40. Thesmaller diameter bore section 382 communicates via a coaxial opening 41with the connecting conduit 36 between the connection fitting 34 and theconnecting bore 35 and therefore communicates with the compressed airnetwork connection 11 so that the supply conduit 15—as alreadymentioned—is disposed on the compressed air network connection 11. Ascan be seen in FIG. 5, the larger diameter bore section 381 communicateswith the working connection 13 via a connecting conduit 42 so that theworking conduit 17—as already mentioned —leads to the working connection13. The working connection 13 is in turn realized by means of a screwsleeve that has an internal thread and is formed into the connectingplate 25. A pressure line leading to a compressed air consuming unit isscrewed into the internal thread of the screw sleeve.

For the connection of the valve housing 24 and connecting plate 25, thevalve housing 24 has radially protruding detent projections 43 (seeFIGS. 1 and 3-7) on its circumference, which snap into correspondingdetent openings 44 in the connecting plate 25. As a result of theO-rings 39, 40 inserted between the plug-in fittings 26 of the valvehousing 24 and the plug-in bore 38, no tolerance problems are producedwhen assembling the valve housing 24 and connecting plate 25. Thesliding together of the two parts is achieved in an extremely shorttime. The disassembly is performed by lifting the detent projections 43out from the detent openings 44 by means of a suitable tool.

For the connection of the directional control valve 10 to the vehicle, afastening plate 45 is formed onto the connecting plate 25 and of onepiece with it, which extends at right angles to the top and bottom ofthe connecting plate 25 as well as to the two plate sides 251, 252 ofthe connecting plate 25 that contain the connection fitting 34 or theconnecting bore 35. In the fastening plate 45, two diagonally disposedfastening eyes 46, 47 are embodied out of injection molded metal sleevesthrough which fastening screws can be guided, which are screwed to thevehicle frame or to a suitable carrier plate on the vehicle frame.

As shown in FIGS. 1-3, on the plate sides 251 and 252 which carry theconnection fitting 34 or the connecting bore 35 of the compressed airnetwork connection 11, connecting means are disposed that are embodiedso that they correspond with one another to produce a mechanicalconnection between two connecting plates 25, 25′ with a connectionfitting 34 and a connecting bore 35 that are plugged into one another(FIG. 4). In particular, on each plate side 251 and 252, respectively,these connecting means include two claws 47, 48 and two incorporatedpockets 49, 50 that are disposed diagonal to one another on each plateside 251 and 252. FIG. 3 shows both diagonally disposed claws 47, 48 andboth diagonally disposed pockets 49, 50 on the plate side 252. The sameclaws 47, 48 and pockets 49, 50 are disposed on the plate side 251 sothat when the plate side 251 of the one connecting plate 25 is placedagainst the plate side 252 of the other connecting plate 25′, thecorresponding claws 47, 48 on the plate side 251 of the connecting plate25 engage in the pockets 49, 50 on the plate side 252 of the otherconnecting plate 25′ and conversely, the claws 47, 48 on the plate side252 of the connecting plate 25′ engage in the pockets 49, 50 in theplate side 251 of the other connecting plate 25′ and thus the twoconnecting plates 25, 25′ interlock with each other. As illustrated inFIG. 14, the claws 47, 48 and the pockets 49, 50 are embodied so thatfor the reciprocal sliding of the claws 47, 48 on the one connectingplate 25 into the pockets 49, 50 on the other connecting plate 25′ andvice versa, the two connecting plates 25, 25′ must be placed againsteach other rotated in relation to each other by an angle α, wherein theconnection fitting 34 of the one connecting plate 25 fits into theconnecting bore 35 of the other connecting plate 25′ (FIG. 4). Then thetwo connecting plates 25, 25′ are rotated back around the flushlongitudinal axes of the connection fitting 34 and the connecting bore35 until the angle α has become zero. By means of this rotation, theclaws 47, 48 slide into the associated pockets 49, 50 and lock the twoconnecting plates 25, 25′ in the axial direction in relation to eachother.

In order to prevent an inadvertent release of the two connecting plates25, 25′ from each other through a renewed rotation of the connectingplates 25, 25′ by the angle α in relation to each other, the connectingmeans also have detent projections 51 and detent openings 52. Two detentprojections 51 are disposed on the plate side 252 on opposite sides ofthe connecting bore 35 of the compressed air network connection 11,wherein they are embodied rotated by 180° in relation to each other. Thetwo detent openings 52 are disposed on the plate side 251 on both sidesof the connection fitting 34 of the compressed air network connection 11so that they correspond to the detent projections 41. When the twoconnecting plates 25 and 25′ that are placed against each otheraccording to FIG. 14 are rotated in the direction of reducing therotational angle α, at the end of the rotation (α=0), the detentprojections 51 on the plate side 252 of the connecting plate 25 engagein the detent openings 52 on the plate side 251 of the connecting plate25′, as is illustrated in FIG. 15. As a result, the two connectingplates 25 and 25′ are secured against turning back and the connectionbetween the two connecting plates 25, 25′ cannot be inadvertentlyreleased. A lifting of the detent connection and therefore a rotation ofthe two connecting plates 25, 25′ in relation to each other is onlypossible after pressing the detent projections 51 out of the detentopenings 52, which can be achieved by means of a flat object.

The modular building-block system of the directional control valvedescribed also includes a closing element 53, as depicted in FIGS. 18and 19. This closing element 53 is used to close the connecting bore 35of the compressed air network connection 11 and for this purpose, has apin 54 that corresponds to the connecting bore 35 and dips into theconnecting bore 35 in an airtight manner with the interposition of aradially sealing O-ring. The same connecting means are disposed on theside 531 of the closing element 53 that has the pin 54, like on theplate side 251 of the connecting plate 25 on which the connectionfitting 34 projects. These connecting means in turn include the twodiagonally disposed claws 47, 48 and the two diagonally disposed pockets49, 50, as well as two detent openings 52. As illustrated in FIG. 14,for placing the two connecting plates 25, 25′ against each other, theclosing element 53 must also be placed against the plate side 252 of theconnecting plate 25 at the same rotational angle α. Through thesubsequent turning of the connecting element 53 back in the direction ofreducing the rotation angle α until α=0, the claws 47, 48 of the closingelement 53 pivot into the pockets 49, 50 on the connecting plate 25 andconversely, the claws 47, 48 pivot into the pockets 49, 50 on theclosing element 53. At the end of the rotational movement, the detentprojections 51 embodied on the plate side 252 of the connecting plate 25engage in the two detent openings 52 in the closing element 53. If thepressure supply line coming from the compressed air network is nowconnected to the connection fitting 34 and the pressure line leading tothe compressed air consuming unit is now connected to the workingconnection 13, and the electromagnet 21 is electrically contacted viathe two-pole plug 30, as shown in FIGS. 1-5, then the 3/2-way solenoidvalve 10 is fully functional.

FIGS. 8-11 show a pneumatic 3/2-way solenoid valve 10′ withelectromagnetic pilot control. The circuit symbol of thispilot-controlled valve 10′ is shown in FIG. 13. To realize thispilot-controlled valve with the modular building-block system, anotherconnecting plate 25′ is provided and is only modified on the inside inorder to accommodate a pneumatically controlled main valve. Thedeliberate connection of the housing 24 to the connecting plate 25realizes an electromagnetically, directly actuated 3/2-way valve 10 andthe connection of the housing 24 to the connecting plate 25′ realizes anelectromagnetically pilot-controlled, pneumatically actuated 3/2-wayvalve 10′. Like the connecting plate 25 in FIGS. 1-5, in an unalteredway, the connecting plate 25′ has the compressed air network connection11 with the connection fitting 34 and connecting bore 35, whichcommunicate with each other by means of the connecting conduit 36, hasthe working connection 13, as well as the connecting means comprised ofclaws 47, 48, pockets 49, 50, detent projections 51, and detent openings52. The stepped plug-in bore 38 is also embodied identically, which withits two bore sections 381 and 382, receives the two fitting sections 261and 262 of the plug-in fitting 26 on the valve housing 24 in an airtightmanner, wherein in turn, the smaller diameter bore section 382 isconnected to the connecting conduit 36 between the connection fitting 24and the connecting bore 35 of the compressed air network connection 11.In a modification in relation to the connecting plate 25, the largerdiameter bore section 381 is not directly connected to the workingconnection 13, but rather to a connecting conduit 79, which is connectedvia a control conduit 55 to a work chamber 56 of a pneumaticallyactuated seat valve 57. The seat valve 57 has a valve opening 58, whichproduces a connection between the connecting conduit 36 and the workingconnection 13. The valve opening 58 is encompassed by a valve seat 59upon which a valve plate 61 fastened to a valve tappet 60 rests. On theend remote from the valve plate 61, the valve tappet 60 is connected toa sliding piston 62 which defines the work chamber 56 on one end. If anair pressure is built up in the work chamber 56, then the sliding piston62 slides counter to the restoring force of a valve closing spring 63,the valve plate 61 lifts up from the valve seat 59, and the connectingconduit 36 is connected to the working connection 13 so that thisconnection is disposed on the compressed air network. When the seatvalve 57 is closed, the working connection 13 is connected to a separatevent 65 via a ventilation conduit 64. At the same time, the ventilationconduit 65 is connected to the guide conduit for the valve tappet 60. Onits free end face remote from the valve plate 61, the ventilationconduit 64 is provided with a valve seat 66, upon which the valve plate61 rests when the seat valve 57 opens and this valve plate 61 closes thevent 65 off from the working connection 13. The vent 12 in the valvehousing 24 is used to ventilate the work chamber 56 of the seat valve57. The seat valve 57, along with the work chamber 56, sliding piston62, valve closing spring 63, valve tappet 60, and valve plate 61 as wellas the control conduit 55 and the ventilation conduit 64 with the valveseat 66 are integrated into a valve body 80 which rests against thebottom of the connecting plate 25′ and is connected to it by means of adetent connection 81 comprised of detent projections and detentopenings. The valve seat 59 of the seat valve 57, which seat encompassesthe valve opening 58 between the connecting conduit 36 and the workingconnection 13 is embodied in the connecting plate 25′.

By way of example, FIG. 12 shows how three of the valves described canbe combined into a valve block 67. Two of these valves arepilot-controlled 3/2-way solenoid valves 10′ and one valve is a directlycontrolled 3/2-way solenoid valve 10. The two valves 10′ correspond invalve structure to FIGS. 8-11 and the valve 10 corresponds in valvestructure to FIGS. 1-5. FIG. 13 shows the circuit diagram of the valveblock 67. The individual connecting plates 25, 25′ and 25′ of the threevalves 10, 10′, and 10′ are described above and are placed against oneanother in the manner illustrated in FIG. 14. The connecting bore 35 ofthe compressed air network connection 11 in the connecting plate 25′ ofthe latter valve 10′ (on the left in FIG. 12) is closed by the closingelement 53 according to FIGS. 18 and 19. The pressure supply line of thecompressed air network is screwed into the connection fitting 34 of thecompressed air network connection 11 in the connecting plate 25 of thefirst valve 10. The flow direction of the compressed air is indicated inFIG. 12 with an arrow 68. The valve block 67 can be attached to theindividual connecting plates 25, 25′, and 25′ on the vehicle via the sixfastening eyes 46. A bus 69 with three plug caps 76 and a connectingplug 70, which is shown in a partially sectional side view in FIG. 16,is for contacting the three plugs 30 of the valve block 67. Theconnecting plug 70 according to DIN 72 585 has four electrical contactswhich are each connected to a strip conductor 71 -74 (FIG. 17) of thebus 69. The strip conductors 71-74 are realized by means of a stampedgrating 75, which is extrusion coated with plastic. Two plug sleeves 77,78 are disposed in each plug cap 76 so that they slide onto the two plugpins 28, 29 of the plug 30 when the plug cap 76 is placed onto a plug 30on the housing 24. All of the plug sleeves 77 connected to the stripconductor 71 and are of one piece with it, while the plug sleeves 78 ofthe first, second, and third plug sleeve 76 are connected to and of onepiece with the strip conductor 72, the strip conductor 73, and the stripconductor 74 (FIG. 17). By sliding the bus 69 with its plug caps 76 ontothe plugs 30 on the valve block 67, all of the electromagnets of thethree valves are electrically connected in a correct fashion.

The foregoing relates to preferred exemplary embodiments of theinvention, it being understood that other variants and embodimentsthereof are possible within the spirit and scope of the invention, thelatter being defined by the appended claims.

I claim:
 1. An electromagnetically actuatable pneumatic directionalcontrol valve (10; 10) comprising a compressed air network connection(11), a vent (12) and at least one working connection (13) for acompressed air consuming unit, a valve member (20) that is actuated byan electromagnet (21) and, for an alternating closure of a workingconduit (17) that leads to a working connection (13) in relation to thecompressed air network connection (11) and the vent (12), isalternatingly placed against one of two valve seats (18, 19) of whichthe one valve seat is embodied at the conduit mouth of a supply conduit(15) that leads to the compressed air network connection (11) andanother valve seat is embodied at the conduit mouth of a ventilationconduit (16) that leads to the vent (12), the electromagnet (21), thevalve member (20), the working conduit (17), the supply conduit (15),and the ventilation conduit (16), along with corresponding valve seats(18, 19) and the vent (12) are combined in a valve housing (24) and theconnections (11, 13) for the compressed air network and the compressedair consuming units are disposed in a connecting plate (25; 25) that canbe separated from the valve housing (24) and is detachably connected tothe valve housing (24), that the compressed air network connection (11)has a connection fitting (34) that is accessible on one plate side (251)of the connecting plate (25; 25), and has a connecting bore (35) that islet into the remote plate side (252) of the connecting plate (25; 25),which fitting and bore communicate with each other and are adapted toeach other so that the connection fitting (34) can be plugged into theconnecting bore (35) of a second directional control valve (10; 10) inan airtight manner with the interposition of a radially sealing O-ring(37), and that connecting means are disposed on each of the plate sides(251, 252) of the connecting plate (25; 25) that carry the connectionfitting (34) or the connecting bore (35), which connecting means areembodied so that the connecting means correspond to each other toproduce a connection between the two connecting plates (25, 25) of thetwo directional control valves (10, 10), with the connection fitting(34) and the connecting bore (35) plugged into each other.
 2. A valveaccording to claim 1, in which a stepped plug-in fitting (26) with twocoaxial fitting sections (261, 262) of different diameters is embodiedon the bottom (241) of the valve housing (24) and a stepped plug-in bore(38) with two coaxial bore sections (381, 382) of different diameters isembodied on the top (253) of the connecting plates (25; 25), that theplug-in fitting (26) can be plugged into the plug-in bore (38) in asealed fashion with the interposition of a radially sealing O-ring (39,40) between each fitting section (261, 262) and the associated boresection (381, 382), that the supply conduit (15) feeds into a circularend face of the smaller diameter fitting section (262) and the workingconduit (17) feeds into an annular end face of the larger diameterfitting section (262), and that the smaller diameter bore section (382)of the plug-in bore (38) communicates with a connecting conduit (36)which joins the connection fitting (34) and the connecting bore (35) ofthe compressed air network connection (11) to each other.
 3. A valveaccording to claim 2, in which the larger diameter bore section (381) ofthe plug-in bore (38) communicates with the working connection (13). 4.A valve according to claim 2, in which in the connecting conduit (36)between the connection fitting (34) and the connecting bore (35) of thecompressed air network connection (11), a valve opening (58) is providedthat is sealed by a valve plate (61) of a seat valve (57) andcommunicates with the working connection (13), that the valve plate (61)is attached via a valve tappet (60) which is attached to a slidingpiston (62) that defines a work chamber (56), and that the largerdiameter bore section (381) of the plug-in bore (38) communicates withthe work chamber (56).
 5. A valve according to claim 4, in which theseat valve (57) is integrated into a valve body (80) connected to theconnecting plate (25), in which valve body a vent (65) and a ventilationconduit (64) connecting the vent (65) to the working connection (13) areembodied, a ventilation conduit feeds freely, with spacing from thevalve opening (58), and that at the conduit mouth, a valve seat (66) isembodied, against which the valve plate (61) rests with the unblockingof the valve opening (58).
 6. A valve according to claim 1, in which theconnecting bore (35) of the compressed air network connection (11) inthe connecting plate (25; 25) can be closed by means of a closingelement (53) that has a connecting means on one side of the element,which correspond to the connecting means disposed on the plate side(252) of the connecting plate (25; 25) that contains the connecting bore(35) to produce a connection, and that the closing element (53) has apin (54) that protrudes into the connecting bore (35) when the closingelement (53) is placed against the connecting plate (24), and seals itin an airtight fashion by means of a sealing ring (37).
 7. A valveaccording to claim 1, in which the housing (24) and the connecting plate(25; 25) can be connected to each other in detent fashion and for thispurpose, detent openings (44) and detent projections (43) that can snapinto them are provided, wherein the detent projections (43) arepreferably disposed on the circumference of the valve housing (24) andthe detent openings (44) are disposed on the connecting plate (25; 25).8. A valve according to claim 1, in which fastening means for spatiallyfixing the connecting plate (25; 25) are provided on a plate side of theconnecting plate (25; 25) that extends at right angles to the two platesides (251, 252) that carry the connection fitting (34) and theconnecting bore (35), respectively.
 9. A valve according to claim 8, inwhich the fastening means include a fastening plate (45) formed onto theconnecting plate (25; 25) and preferably of one piece with it that hastwo fastening eyes (46) preferably disposed diagonally on it.
 10. Avalve according to claim 1, in which the connecting means provided onthe remote plate sides (251, 252) of the connecting plate (25; 25)include two protruding claws (47, 48) and two incorporated pockets (49,50), wherein the pockets (49, 50) are embodied for receiving the claws(47, 48), that the two claws (47, 48) and the two pockets (49, 50) oneach plate side (251, 252) are disposed diagonal to each other on bothplate sides (251, 252) so that after the connection fitting (34) of theone directional control valve (10) is plugged into the connecting bore(35) of another directional control valve (10), the respective claws(47, 48) of the one connecting plate (25 or 25) engage behind thepockets (49, 50) of the other connecting plate (25 or 25).
 11. A valveaccording to claim 10, in which the claws (47, 48) and pockets (49, 50)are embodied so that they are disposed in one another with positiveengagement in the axial direction after the two connecting plates (25,25), which are placed against each other rotated in relation to eachother around the longitudinal axes of the connection fitting (34) andthe connecting bore (35), are rotated back again.
 12. A valve accordingto claim 1, in which the connecting means have detent projections (51)embodied on one plate side (252) and detent openings (52) embodied onthe other plate side (251) and that the detent openings (52) and detentprojections (51) are associated with one another so that after theconnection fitting (34) and the connecting bore (35) of the connectingplates (25, 25) of two directional control valves (10, 10) are pluggedinto each other and after the connecting plates (25, 25) are rotated toproduce the positive engagement between the claws (47, 48) and pockets(49, 50), the detent projections (51) engage in the associated detentopenings (52) and secure the two connecting plates (25; 25) againstrotation around the longitudinal axes of the connection fitting (34) andthe connecting bore (35).
 13. A valve according to claim 1, in whichwinding ends of a magnet coil (22) of the electromagnet (21) are routedto a two-pole plug (30) that is disposed on the valve housing (24), andcan be accessed from the outside, and has two plug pins (28, 29).
 14. Avalve according to claim 13, in which the plug (30) is covered by a plugcap (76) that has two plug-in sleeves (77, 78) that can be slid onto theplug pins (28, 29), that a number of plug caps (76) are connected to anelectric bus (69) that has a number of strip conductors (71-74) realizedby means of a stamped grating (75), wherein one plug sleeve (77) of aplug cap (76) is connected to a strip conductor (71) shared by all ofthe plug caps (76) and one plug sleeve (78) is respectively connected toa different strip conductor (72-74), and that at the other and, all ofthe strip conductors (71-74) are connected to electrical contacts of anelectrical connecting plug (70).